/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 * @param {*} rootId 根Id 默认 0
 */
 export function handleTree(data, id, parentId, children, rootId) {
    id = id || 'id'
    parentId = parentId || 'parentId'
    children = children || 'children'
    rootId = rootId || Math.min.apply(Math, data.map(item => { return item[parentId] })) || 0
    //对源数据深度克隆
    const cloneData = JSON.parse(JSON.stringify(data))
    //循环所有项
    const treeData = cloneData.filter(father => {
     let branchArr = cloneData.filter(child => {
      //返回每一项的子级数组
      return father[id] === child[parentId]
     });
     branchArr.length > 0 ? father.children = branchArr : '';
     //返回第一层
     return father[parentId] === rootId;
    });
    return treeData != '' ? treeData : data;
   }